Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S939855AbXHNCGy (ORCPT ); Mon, 13 Aug 2007 22:06:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754595AbXHNCGp (ORCPT ); Mon, 13 Aug 2007 22:06:45 -0400 Received: from mailgate-out2.mysql.com ([213.136.52.68]:38813 "EHLO mailgate.mysql.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750860AbXHNCGn (ORCPT ); Mon, 13 Aug 2007 22:06:43 -0400 X-Greylist: delayed 1314 seconds by postgrey-1.27 at vger.kernel.org; Mon, 13 Aug 2007 22:06:43 EDT Subject: Re: [PATCH 00/23] per device dirty throttling -v8 From: Stewart Smith To: Brice Figureau Cc: Andi Kleen , linux-kernel@vger.kernel.org In-Reply-To: <1186389638.30448.29.camel@localhost.localdomain> References: <20070803123712.987126000@chello.nl> <20070804063217.GA25069@elte.hu> <1186389638.30448.29.camel@localhost.localdomain> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-+pjuwmzVbFesPQ352XO7" Organization: MySQL AB Date: Tue, 14 Aug 2007 11:44:56 +1000 Message-Id: <1187055897.18858.31.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2286 Lines: 62 --=-+pjuwmzVbFesPQ352XO7 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2007-08-06 at 10:40 +0200, Brice Figureau wrote: > Mysql accesses its database files in O_DIRECT mode. binlog is written using buffered IO. for InnoDB, binlog is synced first, then innodb log. on restart (in 5.0) these are synced back up so you don't get inconsistencies. and from a quick look at the innobase source, only data file is using O_DIRECT. > Since the database fits in RAM, the only kind of access Mysql is doing > is writing to the innodb log, the mysql binlog and finally to the innodb > database files. > There are certainly a whole lot of fsync'ing happening. yes. Keep in mind that the binlog grows in file size too... so this has to sync all the metadata as well (ick, i know). --=20 Stewart Smith, Senior Software Engineer MySQL AB, www.mysql.com Office: +14082136540 Ext: 6616 VoIP: 6616@sip.us.mysql.com Mobile: +61 4 3 8844 332 Jumpstart your cluster: http://www.mysql.com/consulting/packaged/cluster.html --=-+pjuwmzVbFesPQ352XO7 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iQIVAwUARsEJGL3yNwHyU3DLAQIJAQ//XsnJ0jQvxuPPT48LIJoeBX2eejc0ISVs 3aN+5mMkIy/nI8LlfUNfmsCCCWwo5j2Mj/AHG+gtM3F2xWOYqfnX0dAg9kJRu3j4 lctPzQ/aj4qhBQ8FBHnH7i0vfvN/ydxs1u8ebBiqDYl0djukt74pBJBNuKAd8zK6 IbfqJcew8T/25+zVxz7rfZF6ghmh+TlgglYikM3tJs61ZK7SS0We9ZHo0L98pG7U MXMDBrQIZ2+Xoe/vRXTkYhkYHGd5p8JnXFBUTtY8C8harPglyyDjbIeI2VGFN5mZ taYqhbUnfnHgf3WoXSzaN336GCqa/nII1n0XiSU53kk4UTKtgYUQLZchTATV1UBQ ZG1keeb/2MNsIHcMwrRJfwV/Omv+1Gi0dzxM7JQQap0CJX86vkL7L2O37nvOxXto UABErSKU4e/2TMPtOVgaPAnh9ZzKgPUsI/qiXxeWWHrzIDZX3MPmjOmpDQSVj1a+ O6Uhb9YjhPk9nO/juyxd8pSez+lwmRnfBrm5gXqmtamcdyDL/+UzdOnq4F+6gbS1 sO8ksnSp4DwyE7TuEm2Tq4aguCGX4rqV1SaCFshssJaFVTfR4n8y+wMz2xPaAwoi C5RKCDL512hY4LXyO0PgtsGgnfAcsomdUX9S39AKFrvkPZJcOPh3aWRWD8DBmaZf zXnj3BKMlUc= =WxnS -----END PGP SIGNATURE----- --=-+pjuwmzVbFesPQ352XO7-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/